Achieving Fair Performance by Power Allocation in Opportunistic Cooperation

We consider a wireless opportunistic network where one of the lucky users gets the opportunity to utilize the whole radio resource. However some of unlucky users keep silent during an unexpected time resulting from serious wireless environment. In this paper we propose an opportunistic cooperation protocol that can achieve equal performance measured in terms of outage probability, in which scheme the opportunistic user helps to relay what need retransmitting indicated by the destination and selects the appropriate power allocation to pursue fairness. We utilize superposition coding and successive interference cancellation at relay and destination, respectively. To improve the spectral efficiency we give a modified cooperation architecture involving two opportunistic users which work in turns. The simulation results have proved that the protocol obtains better performance compared with the conventional methods.